[20-04-29][Self-test 22]Java WhatNum

 1 package test_4_1;
 2 
 3 public class WhatNum {
 4 
 5     public static void main(String[] args) {
 6 
 7         /** 809*??=800*??+9*??+1
 8          * 其中??代表的两位数,8*??的结果为两位数，9*??的结果为3位数。求??代表的两位数，及809*??后的结果 */
 9         
10         getNum();
11         
12     }
13 
14     private static void getNum() {
15         
16         for (int i = 10; i < 100; i++) {
17             if (8 * i < 100 && 9 * i > 100 && 809 * i == 800 * i + 9 * i) {
18                 System.out.println("值为：" + i);
19                 System.out.println("809 * " + i + " = " + i * 809);
20             }
21         }
22         
23     }
24 
25 }